Changelog:
* Support for transparent fail-over based on Metalink, supported by all read I/O with HTTP
* Multi-Range support compatible with TDavixFile/ROOT 5/6
- Tested for dCache, DPM, Apache2, EOS, DynaFed, Owncloud, S3
* Implement SOCKS5 support based on libneon
* Add support for POSIX write operations, davix can now be used to write remotely on top of POSIX layer.